Fräu|lein (abbrev. Frl.) is a German title like
Herr or Frau. Usage: "Guten Morgen, Fräulein
Müller!" It was used up to around 1980 to address unmarried women,
today it's discouraged because it is a diminutive form of Frau
and feminists argued that men don't have to disclose their
marital status in their title, so why should women?
Today, Fräulein is used to address little girls, sternly or
quipping. A young woman addressed in this way might react
offended, a grown woman doubly so.
Fräulein is one of the few words that the actors portraying
the stereotypical German soldiers in old Hollywood
war movies use to indicate that the audience should imagine they are
speaking German, while they are obviously speaking English. As in:
"Get Fräulein Braun's luggage to her room and then
bring the British war criminals for interrogation. Mach schnell."
"Jawohl, Herr Obersturmbanngauleitermeisterführer!
Follow me, Fräulein Braun, please."
This makes the scene more accessible to illiterates, because there's
no need to subtitle it, while at the same time putting less pressure on
the actors who are already challenged pronouncing one German
word correctly, let alone a whole phrase.
In exaggeration, this can be seen
in every episode of Hogan's Heroes.
Uses of the word Fräulein in titles of pieces of art include
E.T.A. Hoffmann: Das Fräulein von Scuderi or
Fräulein Smillas Gespür für Schnee
(as this is a 1997 movie, one has to wonder why someone chose to use the
exact word-by-word translation as the German title).
Idioms using the term: Fräulein vom Amt (phone
operator) or Fräuleinwunder (a term describing the success of
young women in West Germany's post-WW2 society).